You are here:

Aviation/Flying/Mach --> KIAS conversion

Advertisement

Expert: Capt Paul - 11/23/2006


Question
Dear Captain Jeeves,

I would appreciate your assistance regarding the following:

1. How does one convert Mach number to KIAS dependant on altitude?

e.g.

Mach Speed: 0.8
KIAS: ?
Altitude: 30,000

Thank you for your help.

Kind Regards,

Ori


Answer
Hello,
  As a general rule, the following formulas will work…

Mach = Kts divided by 60
Kts = Mach multiply by 60

For more accurate computations, you would need the actual temperature at 30000 feet.  Then, the local Mach number can be found on an E6B Whiz wheel or flight Calculator.

Assuming that the temperature is -45 at 30,000 feet, the local speed of sound would be 588 knots.    Therefore mach .80 would be equal to 470 Knots.  

Aviation/Flying

All Answers

Answers by Expert:

Ask Experts

Volunteer

Capt Paul

Expertise

I can answers questions relating to: aircraft and airline operations; aircraft technical matters relating to a number of different aircraft types; flight operations & flight planning; Aviation meteorology; accident prevention and investigation; the Air Traffic control system and how pilots interact with it; and pilot and airline licensing in the Europe, Asia, Canada and the US. I also answer questions about all types of Navigation, Aviation Weather, Aircraft Performance, Procedures and Aviation law (in general).

Experience

Current Airbus Captain with over 23 years as an airline pilot and over 13,500 hours of experience. Also experience as a Flight Operations Manager/Director; Chief Pilot; Instructor; Safety Officer, and training as an Accident/Incident Investigator.

Education/Credentials
Degree in Airline / Aerospace Operations. Minor in Behavioural Psychology and studies in pre-law. BS, Aerospace

©2012 About.com, a part of The New York Times Company. All rights reserved.